Improvement in hydraulic railway brakes



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GEORGE PEARSON RENSHAW, OF PARK VALLEY, ENGLANDQ IMPROVEMENT IN HYDRAULIC-RAILWAY BRAKES.

Specification forming part of Letters Patent No. 136,617, dated March 1p1, 1873.

To all whom 4it may concern:

Be it known that I, GEORGE PEARSQN REN- SHAW, of Park Valley, in the county ot' Nottingham, England, have invented certain new and Improved Hydraulic Railway Brakes;

and I do hereby declare that the following is a full, clear, and exact description thereof,

reference being had to the accompanyin g drawments shall give its own proportion of brakepower to the train, and shall be capable of exerting such power independently ofthe accidental failure of the brake apparatus of one or more of the other connected carriages by negligence or otherwise; also, 4so that the train shall admit of being-divided, and in which case the brakes in each part will act separately. The nature ot' my invention consists, first, in the application of the natural pressure resulting from the superposition of a head of water to actuate the brakes of railway-carriages, by means of .water admitted to cylinders or chambers with iiexible diaphragms, bellows, or other equivalent apparatus; secondly, in the subsequent raising of the water so applied, by means of fans or arms y secured upon the revolving'a-Xles of the carriages, whereby the water, after having actuated the brakes, can be returned to the reservoir or transferred to the tender or feed-tank of the boiler 5 and, thirdly, in constructing and arrangin g the valves w hich operate the brakes in such a .manner thatjby means of cords or other flexible connections they shall be under the control of eithervthe guard or the enginei driver, or both, and so as, in the event of breakage of the connecting couplings of the train, to cause lthe brakes to act instantaneously and automatically;

In order that lmy invention may be fully understood, I will now proceed toa more particular description thereoffreferrin g to the accompanying drawing, v`in which- Figure 1 represents alongitudinal sectional elevation of an ordinary railway passengercarriage with my improved hydraulic brake attached; Fig. 2, an end or transverse elevation of the same; Fig. 3, a detail sectional view of one of the chambers or cylinders. Fig. 4 shows the arrangement of the cord or chain for operating the valve so as to admit water to the' chambers, and Fig. 5 shows one mode which I employ for returning the Water to the feed-tank or tender. i

The same letters of reference indicate corresponding parts in all the ligures.

' A is a cistern or reservoir, supplied when necessary with water through the nozzle or spout B. This cistern A may be placed beneaththe carriage-seat, as shown, or, at'option, it maybe ixed on the carriage roof or back, or in any other posit-ion, as desired; but always at a suflicientelevation above the moving details ofthe brakes to secure hydrostatic power. The cistern A is connected with a small receiver, O, by means of a pipe, D, and also with one or more pressure-cylinders or diaphragm-chambers, E E E, by the pipe F. One of these cylinders or chambers is shown in detail section on a larger scale at Fig. 3, and is hereinafter more fully described. The cylinders or chambers E are firmly attached `to the framing of the carriage by an intermediate framing, and on their tops are corresponding disks orcovers G G G, which are lifted through a small space when water from the cistern A is admitted to the cylinders or chambers E through the supply-pipe F. Between the up-.

per surface of each of the cylinders or chambers ,E and the under surface ot' the corresponding disk Gr a diaphragm of India rubber strengthened with cloth, or of leather or other exible material impermeable to water, is placed to prevent leakage. 'lhe disks G act on the lever H, which is connected with one or more brake-blocks, I I, through the intermediate coupling rods or links shown in Fig. l; but, if desired, the pressurel cylinders or chambers E may have their axes horizontal, and so act directly on the brake-blocks I without the intervention of the lever H. I prefer, however, the first arrangement. Itwill also be obvious that the disposition of the pressure cylinder's or chambers E with their attaching fra-ming, and of the other adjacent parts,'sev erally, may be varied to suit the general arlimi` l rangement of the carriage, whether provided with brakes between thewheels requiring to be pressed asunder and in opposite directions, or with brakes (as shown in the drawing) which require to be pulled in the same direction. The hydraulic power may also be applied on either one or. both sides of the carriage, and equally to what are known'as iiap `or to sliding brakes., The admission of the water to the pressure' cylinders or chambers E, and the consequent application ofthe brakeblocks to the wheels, is regulated and governed by an inlet-valve, K, andthere is likewise an outletvalve, L, located below on the same or a ditl'erent rod, by which latter valve the water may'escape from the pressure-cyliuders or chambers E into the catch trough or troughs M when it is intended to cause the braking power to cease. The brake-blocks I are then removed from the wheels by the combined weights of the disks Gr and lever H, supplemented, if necessary, for that purpose. The valves K and L, if on the same rod, are made cylindrical on a portion of their length, and filling the orlices in their respective valveseats` and in all cases so that the exit-valve L may not open until the inlet-valve K has closed in order to prevent a waste of water. From the catch-trough M the discharged water runs through small apertures in the side of the fan-casing N, which surrounds one of the runnin g-aXles O of the carriage. 'lhis fan-casing N is -suspended at one end from a cross-bar which rests on the opposite axle-boxes by a rod made adjustable in length, and at the other end it is hinged to the supply-pipe F or other suitable part of the framing, so as to be ableto rise and fall with the play ofthe springs. The fan-casingN may be of wood or other material imperfectly conducting heat, to prevent freezing in cold weather. It should also be put on the axle in two parts. A cock, lf, is likewise provided, by which the water may be run oli" at such Ytimes as the carria ge isrequircd to stand in Iresiding or other exposed place. '.lhe constant agitation ofthe water, the normal state of emptiness of the pressure cylinders or chambers E, and the short time; the water remains in the catchtrough M, however, will ordinarily be suflicient to secure immunity from injury to the action of the brake at ordinary temperatures, and in extreme cases it will be easy to introduce surlicient boiling water to prevent the working water from freezing. Within the fancase N a fan or dash wheel, Q, is fixed by screw-clamps on the carriage axle O, and consequent-1y revolves with the latter. Thisfan, by centrifugal force, throws the water up one or other of the inclined spouts R B., according to the direction of the motion of the train, and returns it to the original level in the cistern A 'andthe connected supplementary receiver C; or, otherwise, the discharged water may be used to supplement the supply offeed-water in the tender or tanks, inthe manner hereinafter explained 5 or it may be allowed to run to waste.

S S are joints in the inclines, covered with In'- dia-rubber rings to allow ,for`play." If necessary, the fan may be made to act as an ordinary centrifugal pump, raising the water up vertical pipes to the cisterns; but the inclines shown would seem more generally suited -to the varying velocities-of a railway train,

and the usual arrangements of the carriages.

Fig. 3 shows one of the pressure cylinders 'or chambers before referred to in section, on an enlarged scale; c being the cylinder of castiron; G, the movable Vdisk or cover; c, the connecting-passage for the water; and d, the flexible diaphragm. The surfaces between the latter are com pressed and secured, and may be roughened by being turned with a coarse cut or left in rings in order to hold the ilexible material more firmly.

Fig. 4 shows the arrangement of the cord or chain for allowing the valve Kto admit water to the pressure cylinders or chambers E, and so apply the brakes at the will of the guard or driver. This cord or other tlexible connection is passed over pulleys on the carriages from the guards van in the Qrear of the train to the tender or engine at its front, in the same manner as the commonly used cord cour municating between guard, passengers, and driver. 1f any carriage in the train is not fitted with the hydraulic brake, the'cord is simply passed by it and on to the next.

The cord is shown passing under pulleys e e, working the valve-rods by means of levers, in such manner that when the cord is tense the inlet-valves K vare kept closed, and consequently the pressure cylinders or chamber E empty, andthe brake-blocks I off the wheels;

and, conversely, when the cord is slackened, a spiral spring, f, or a suitable weight then causing the inlet-Valves K to beopened -but allthis arrangement may evidently bereversed, as the cylinders or chambers may be ordinarily lled with water, and the cord normally slack, though this alternative plan does not appear so expedient. The communicating-cord g is fastened at the one end around a wheel in the guards van, by which it may be woundiu to suit the length of the. train, in the usual manner, while the other end is secured to theperiphery of a light wheel von the tender or engine, andaround which it is coiled, and either of these wheels is capable of being iXed or released at pleasure by a detent, h. A certain degree ofV tension or strain is kept on the cord g by means of a tension-weight and pulleys, as shown in Fig. 4, or other suitable arrangement in the guards van, and the rapid opening of the inlet-valve K and closing of the outlet-valve L, and consequent operation of the brakes, are promoted by the spiral spring or weight at f. If the cord g be broken by any of the carriages becoming detached, the valves will necessarily be actuated, and the brakes applied automatically in the same manner as bythe ordinary slacking of the cord by the guard or driver.

lt is evident that the temporary applicawaere y l e' tion of the brakes by the guard may be used A by him as a signal toy the engine-driver; and,

also, if the cord be violently pulled down by an aii'righted passenger, itmay be made to cause a bell to strike similar to those fixed to give alarm by raising the tension-weight. Thus the same cord may serve for all purposes of intercommunication in the train. In certain cases a small stream of water may be diverted from the supply-pipe F onto the brake-blocks to prevent them firing in hot weather; or, with cast-iron brake blocks, the water may enter the hollow interior, and' so keep them cool.

To illustrate the power of the brake, if we take the cistern A as containing seven gallons or seventy poundsavoirdupois of water, (and which will suice for two consecutive actions,) and the average head of water (as the pressure will diiier in the cylinders or chambers E) at two feet, and. also the diameter of each of Vthe three pressure-disks G at eighteen inches,

the net pressure on the brake-blocks will be about twelve hundred-weight if the leverage at H is as two to one. v

At T in Fig. l is shown a handle connected with the valves K and L in the supply-pipe F. This handle is to enable the porters or other attendants of the train to shut the inletvalves K, and so prevent the operation of the brakes while separating carriages from or adding carriages to the train at stations, and the handle is capable of being fixed up by a pin and chain to keep the valve K shut -and the brakes olf. f i Y Fig. 5 shows an arrangement by which the water raised up either ofthe inclines' bythe y revolution of the fan runs from the one or the other receptacle into the catch-trough of the next carriage to bel again lifted and so transferred and caused'to iiow on till it reaches the feed-tank or ten der to be used to supplement the supply for` replenishiu g the water inthe boiler. The object of this arrangement is to supersede the necessity for a separate tender in certain cases. In short and what are called local trains,77 made up of a very limited number of ple of their designfor example, bellows like the well -known hydrostatic bellows may be substituted for the cylinders or chambers with iiexible diaphragms; or ramsor pistons may be employed as used in hydraulic presses.

The principal special advantages secured by my invention are as follows: First, the brakes admit of being applied by either the guard or the engine-driver, and, while being simple in construction, and not requiring frequent attention to keep them in working order, they act powerfully and smoothly on the wheels of the carriages to retard and stop the train. Second, in the event of part of the train becoming detached by reason of the severance of the couplings connecting the several carriages, thewhole of the hydraulic brakes at once apply themselves automatically to arrest the revolution of the wheels in the several and i Aand fracturing steel tires in frosty weather.

Fourth, in taking on carriages at junctions, carriages not fitted with these special brakes admit of being worked in conjunction with others so fitted.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, 'is'- 1. The chambers E provided with the disks G and diaphragms d, operated by the pressure of a head of water through the medium of the `cistern `A and pipe F, in combination with the brake-block I, substantially as herein shown and described.

2. The fans Q clamped ouA the axle O, and operating within the casing N by the motion ofthe carriage, in combination with the inclined spouts R R, cistern A, receiver G,and pipe D, substantially as andfor the purposes set forth. 3. The combination of the cords g, springl or weight f, and valves Kand L with the chambers E and brake-block I, all being arranged and operated substantially as andffor the purposes herein set forth. j "fi i GEO. Pf. RENSHAW. -Witnesses f GEO. J. B. FRANKLIN, JNO. GEO. PEARsoN. 

